Crash: A Tale of Two Species

S1, E1: The horseshoe crab produces millions of eggs every spring that are the lifeline for a tiny bird called a red knot, which migrates 10,000 miles from South America to the Arctic each year. But horseshoe crab numbers are crashing from their uses as a testing agent for drugs and vaccines and bait for the fishing industry. Their untold story is a living example of how every species is interconnected.